The natural history of the growth of the hand: I. Hand area as a percentage of body surface area

The use of a patient's own hand as a tool to estimate the area of burn inju ry is well documented. The area of the palmar surface of one hand has been estimated to be 1 percent of the body surface al ea. The area of the palmar surface of the hand was measured to test the accuracy of this estimate and then compared with the body surface area as calculated by formulas in comm on use. This study also sought to determine the natural history of the grow th of the hand to permit development of a readily available, bedside means of estimating hand area and body surface ar ea. Bilateral hand tracings wer e obtained from 800 volunteers ranging in age from 2 to 89 years. The area of each tracing was determined using an integrating planimeter. The height and weight of each individual were measured. and his/her body surface area was calculated. The palmar hand's percentage of body surface area was deter mined by calculating the quotient for hand area divided by body surface are a. Additionally, the width of the hand was measured from the ulnar aspect a t the palmar digital crease of the small finger to the point where the thum b rested against the base of the index finger. The length of the hand was m easured from the middle of the interstylon to the tip of the middle finger. These two figures were multiplied together to obtain a product which appro ximated the area of the hand. Based on the most commonly used DuBois formul a for calculating body surface area, the area of palmar surface of the hand corresponds to 0.78 +/- 0.08 percent of the body surface area in adults. T he percentage varies somewhat with age and reaches a maximum of 0.87 +/- 0. 06 percent in young children. Multiplying the length of the hand by its: wi dth overestimates the area of the hand as determined by planimetry by only 2 percent. A patient's own hand may be used as a complementary, readily ava ilable template for estimation of burn area or other areas of disease or in jury. In adults, the area of tracing of the outline of the hand is 0.78 per cent of the body surface area, whereas in children, this number tends to be slightly higher. In the emergency room or oil the wards, a simple product of length multiplied by width of the hand will closely approximate the area s as determined by planimetry. This method allows a more accurate determina tion of the area of the palmar surface of the hand than the 1 percent estim ate, which may lead to an overestimation of the size of a burn wound in adu lts.